Tesla patented a new cylindrical cell design. In hindsight, it sounds obvious and a good idea, but fabricating this sounds very tricky. Here's what a current Tesla 2170 cell looks like when it is unrolled:
The black sheet on the left is one of the electrodes and the short horizontal tab about halfway up is the tab that collects current from that entire 32" long sheet. When built this way (and all cylindrical cells are currently built this way), current from the top or bottom of that 32" long sheet has to travel a long way along that electrode to get to the current collector tab. This creates heat and even hotspots over time, both of which are problematic. The hotspots in particular shorten cell lifetime.
Tesla's patent is to create a current collector that would go all along one of the 32" long edges of the electrode material. Sounds simple and obvious, right? But when the battery cell is rolled up, that current collector is now a tightly wound spiral that can't touch the other electrode that is on the other side of a thin separator sheet. Basically, this is really hard to manufacture.
But patents don't cover how to manufacture something, just the invention itself. So Tesla gets to patent this idea, no matter whether they've figured out how to make it or not. Eventually they'll be able to mass produce it.
Anyways, nice idea, nice patent. Should go a long way towards making even longer lived battery cells. Will probably allow cells to discharge faster too (less heat), so more peak power.
Article about it here: Tesla Gained Another Battery Cell Patent: Cell With A Tabless Electrode
The black sheet on the left is one of the electrodes and the short horizontal tab about halfway up is the tab that collects current from that entire 32" long sheet. When built this way (and all cylindrical cells are currently built this way), current from the top or bottom of that 32" long sheet has to travel a long way along that electrode to get to the current collector tab. This creates heat and even hotspots over time, both of which are problematic. The hotspots in particular shorten cell lifetime.
Tesla's patent is to create a current collector that would go all along one of the 32" long edges of the electrode material. Sounds simple and obvious, right? But when the battery cell is rolled up, that current collector is now a tightly wound spiral that can't touch the other electrode that is on the other side of a thin separator sheet. Basically, this is really hard to manufacture.
But patents don't cover how to manufacture something, just the invention itself. So Tesla gets to patent this idea, no matter whether they've figured out how to make it or not. Eventually they'll be able to mass produce it.
Anyways, nice idea, nice patent. Should go a long way towards making even longer lived battery cells. Will probably allow cells to discharge faster too (less heat), so more peak power.
Article about it here: Tesla Gained Another Battery Cell Patent: Cell With A Tabless Electrode
